For the past few years, the Transportation Security Administration has deployed its Visible Intermodal Prevention and Response, or VIPER, teams to oversee security at the street level.
"We've conducted several thousand VIPER operations at non-traditional TSA transportation modes: train stations, bus depots," said TSA spokesman Nico Melendez. "Our job is not solely airport security. It's transportation security."
TSA agents this year randomly dropped in unannounced on more than 9,300 mass transit centers to conduct security checks.
Even so, it's not enough to convince some travelers it will prevent an attack from happening.
"We've had some pluses to that in the past few years - stopping things," said Frank Bell of Hemet, "but once again if someone is determined, then they're determined."
The Department of Homeland Security, which TSA falls under, wants to add 12 more VIPER teams to its roster of 25 in 2012. Congress would have to give its approval and allocate additional funding.
"They are successful in deterring any kind of threat to transportation systems, but it is also effective in thwarting any people who want to break the law," Melendez said.